1. Field
Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to multichannel access where multiple simultaneous transmissions can span multiple frequency bands.
2. Background
In order to address the issue of increasing bandwidth requirements that are demanded for wireless communications systems, different schemes are being developed to allow multiple user terminals (i.e., stations) to communicate with a single access point by sharing the channel resources while achieving high data throughputs. Multiple input multiple output (MIMO) technology represents one such approach that has recently emerged as a popular technique for the next generation communication systems. MIMO technology has been adopted in several emerging wireless communications standards such as the Institute of Electrical Engineers (IEEE) 802.11 standard. IEEE 802.11 denotes a set of Wireless Local Area Network (WLAN) air interface standards developed by the IEEE 802.11 committee for short-range communications (e.g., tens of meters to a few hundred meters).
Utilization of the Aggregate Physical Layer Protocol Data Unit (APPDU) was previously considered as a time division multiple access (TDMA) technique, while a single frequency band is utilized. The cost of training to multiple Stations (STAs) can be reduced by employing a common preamble before data transmission. Each STA's transmission can be preceded by a Very High Throughput Signal (VHT-SIG) frame which informs the STA of its modulation-coding scheme (MCS) as different STAs can potentially have different MCS.
However, there is still a need in the art for a method to further increase transmission data rates and to more efficiently utilize available channel bandwidth.